Let's turn now to an example of a prime and analyze the routes through it. Here is an intended function:
[ if a is zero -> x := 0 else if b is positive -> x := y + 1 else -> x := y - 1 ]
The possible paths through this prime are governed by two conditions, which we will call C1 and C2.
a is zero.
b is positive.
There are three paths through the code, because if C1 is true, we don't care whether C2 is true or not. So our truth table has three cases.
|F||F||C1′ ∧ C2′|
|F||T||C1′ ∧ C2|